Forgive me M2 for I have sinned, it's been x amount of time since I last posted... I loved my S that I had and want a S engine for my kit car.

My question is, how tolerable is the ECU, I can go aftermarket on the ECU if needs be, but I would like to keep the original, I would need to lose the ABS, traction control, air con ect, would the ECU spit it's dummy?